Mirror finger patterns of apparent monozygotic twins and sib pairs with Schizophrenia

BACKGROUND: Although mirror images are noted in some twins, no such reports are available for twins and subjects with schizophrenia. AIM: The study was to assess the occurrence of mirror image finger patterns in apparent monozygotic twins with schizophrenia. Another objective was to elucidate these characteristics among sib pairs with schizophrenia for comparison with those of the twins. MATERIALS AND METHODS: Eight apparent monozygotic twin pairs and eight sib pairs with schizophrenia were investigated. The frequency of identical patterns in the right side finger of one twin and the corresponding left side finger of the other twin was assessed, and similarly on other sides. Similar assessment was made in sib pairs with schizophrenia and normal sib pairs. RESULTS: The left middle finger pattern of one of the twin pair was found to be the mirror image of the right middle finger of the other twin in all the twin pairs studied and so was in seven of the sib pairs with schizophrenia. These mirror images of sib pairs with schizophrenia was more than those of normal sib pairs. This difference was accentuated with significantly more of these patterns in the twins in comparison to those among normal sib pairs. Notably, no difference emerged between the sib pairs with schizophrenia and the twins in any of their finger pairs. CONCLUSION: Mirror images that are probably due to factors like abnormal genotypes and L- DNA, appear to be promising tools to study the etiology of schizophrenia.